Title of Invention	AN IMPROVED PROCESS FOR THE PRODUCTION OF NAPHTHALENE SULPHONATE FORMALDEHYDE CONDENSATE ADDITIVE FOR COAL WATER SLURRY FUELS.
Abstract	The present invention relates to an improved process for the production of naphthalene sulphonate formaldehyde condensate additive for coal-water slurry fuels. The main usage of the invention is in the preparation of high concentration coal-water slurry fuel achieving desirable flow property and stability. The process steps are: characterized in that sulphonation of naphthalene at a temperature in the range of 130-165°C, for a time period in the range of 2-8 hrs, condensing the resulting naphthalene sulphonic acid with formaldehyde, cooling to ambient temperature and neutralizing the condensation product with alkali metal hydroxide followed by drying to obtain naphthalene sulphonate formaldehyde condensate.

Title of Invention

AN IMPROVED PROCESS FOR THE PRODUCTION OF NAPHTHALENE SULPHONATE FORMALDEHYDE CONDENSATE ADDITIVE FOR COAL WATER SLURRY FUELS.

Abstract

Full Text	The present invention relates to an improved process for the production of naphthalene sulphonate formaldehyde condensate additive for coal-water slurry fuels. The main usage of the invention is in the preparation of high concentration coal-water slurry fuel achieving desirable flow property and stability. Reference may be made to patent Nos.JP 1062392 dated 08.03. 1989 and JP 1054097 10.3. 1989 wherein additives for coal water slurry (CWS) containing compounds prepared by sulphonating (alkyl) naphthalene, anthracene and biphenyl and condensing with formaldehyde & fatty acids, have been described. Reference may also be made to patent Nos. JP5271674dt. 19.10.1993, JP 1062391 dt 08.03.1989, JP 1054097 dt.01.03. 1989, JP 1182392 dt.20.07.1989 and JP 63156891 dt.29.06. 1988, wherein additives for coal water slurry - containing formaldehyde condensates of naphthalene/(alkyl) naphthalene sulphonic acids, fatty acids and polyethylene polyamine fatty acid amide compounds or compounds obtained from ethylene oxide and alkyl phenol/ polyhydric alcohols etc, have been described. The drawbacks of the above processes are that reactions have to be carried out in several stages with various types of specific compounds and the final additive package requires extensive pretreatment and selective purification methods, thus making the process tedious and uneconomical. Besides, the performance of the additive packages was not upto the desired level. Owing to these disadvantages of naphthalene based additives, the Japanese developed an efficient additive, namely sodium polystyrene sulphonate (PSS) which is used for commercial production of coal-water slurry (Ref. H.Arai and T.Ukigaki, Proc.16 Int. Tech. Conf. Coal Utilisation and Fuel System, Florida(1991) 423-433 ). PSS being the proprietary additive package of a Japanese company, its preparation methods are fully guarded and the additive is highly expensive Reference may also be made to work of J.L. Morrison, B.G.Miller and A.W. Scaroni, Proc. 18 Int. Tech. Conf. Coal Utilization and Fuel Systems, April 26-29(1993) 361-368, Florida, U.S.A., wherein an ammonium based sulphonated naphthalene condensate has been used a s the dispersant for coal-water slurry fuels. However, the slurry formulation with this dispersant requires a pH modifier & a stabilizer. The main object of the present invention is to provide an improved process for the production of naphthalene sulphonate formaldehyde condensate additive for coal-water slurry fuels which obviates the drawbacks as detailed above. Another object of the present invention is to remove the tedious pretreatment and purification steps involved in hitherto known processes for the preparation of sulphonated naphthalene/alkyl naphthalene based additives. Still another object of the present invention is to develop an additive package most suited to low-rank Indian coals for production of coal water-slurry fuels having desired viscosity and stability. Yet another object of the present invention is to develop a low-cost, environmentally safe naphthalene based additive package. Accordingly the present invention provides an improved process for the production of naphthalene sulphonate formaldehyde condensate additive for coal-water slurry fuels which comprises; characterized in that sulphonation of naphthalene at a temperature in the range of 130-165°C for a time period in the range of 2-8 hrs, condensing the resulting naphthalene sulphonic acid with formaldehyde, cooling to ambient temperature and neutralizing the condensation product with alkali metal hydroxide followed by drying to obtain naphthalene sulphonate formaldehyde condensate. In an embodiment of the present invention naphthalene is first sulphonated with 98% sulphuric acid to produce naphthalene sulphonic acid which is then condenesed with formaldehyde at a temperature in the range of 60-110°C for a period in the range of 10-20 hours. In another embodiment of the present invention the formaldehyde condensate of naphthalene sulphonic acid is neutralized with alkali metal hydroxide to a pH of 7.0-9.0 In this process, naphthalene is sulphonated with 98% sulphuric acid in the temperature range of 130-165°C for 2-8 hours. The naphthalene sulphonic acid produced is then condensed with formaldehyde at 60-110°C for 10-20 hours. The condensed mass is neutralized with alkali metal hydroxide to a pH 7.0-9.0 and then dried to obtain naphthalene sulphonate formaldehyde condensate which is used as an additive in the formulation of coal-water slurry fuel. The novelty of the present invention with respect to the prior art lies in that the process provides a state of the art technology for the production of a naphthalene based additive which apart from being cost-effective is very efficient and environmentally safe agent and is also most suited to the lowO-grade Indian coals for the production of coal water slurry fuels. This additive is capable of incorporating high coal-loadings (60-70%) in the aqueous medium providing desirable viscosity and stability to the slurry fuel. The inventive steps are-- 1. The process which is apart from cost effective is very efficient and environmentally safe agent. 2. The process is most suited for to the low grade Indian coals for the production of coal water slurry fuels. 3. The additive used is capable of incorporating high coal- loadings(60-70%) in the aqueous medium providing desirable viscosity and stability to the fuel. The following example is given by way of illustration of the present invention and therefore should not be construed to limit the scope of the present invention. EXAMPLE-1 533 gms. of 96% naphthalene is melted, 440 gms. of 98% sulphuric acid is added gradually to it and temperature of sulphonation reaction maintained at 160°C for 5 hours. The sulphonated mass is cooled and 220 ml water is added. To this mixture 228 ml formaldehyde solution (37%) is added slowly, the temperature is raised to 75°C and the reaction is carried out for 20 hours. At the end of this period the mixture is gradually heated to 110°C.The reaction product is cooled to ambient temperature and then neutralised with aqueous sodium hydroxide solution. The neutralised mass is dried to get sodium naphthalene sulphonate formaldehyde condensate which functions as an excellent additive in the formulation of coal water slurry fuels. The invention has led to a simple process for the production of naphthalene sulphonate formaldehyde condensate which apart from being cost-effective, is an environmentally safe agent for use as an additive in the formulation of coal water slurry fuel. Secondly, the process steps have been reduced to a minimum and no by-products or any effluent are produced in the process. Thirdly, the reactions are carried out at relatively lower ranges of temperatures and at atmospheric pressure thereby leading to considerable savings in energy consumption in the process. The salient features of the invention which have an edge over the known processes are : 1. That the main feedstock naphthalene as well as other reactants are easily and cheaply available. 2. The consumption of raw materials are considerably less. 3. The reactions are carried out at relatively lower ranges of temperatures and at atmospheric pressure thereby reducing the energy consumption. 4. No effluent is produced in the process making it an eco-friendly. 5. The developed additive packag^ functions excellently at concentration of 0.6- 1.00%(on dry coal basis) with low- rank Indian coals incorporating high coal-loadings (60-70%) in aqueous slurry and providing desirable flow property/viscosity as well as stability to the slurry fuel. 6. The additive has a shelf life / stability of 9-22 days and viscosity in the range of 400-1000 mPas at 128 sec-1 We Claim: 1. An improved process for the production of naphthalene sulphonate formaldehyde condensate additive for coal-water slurry fuels which comprises; characterized in that sulphonation of naphthalene at a temperature in the range of 130-165°C for a time period in the range of 2-8 hrs, condensing the resulting naphthalene sulphonic acid with formaldehyde, cooling to ambient temperature and neutralizing the condensation product with alkali metal hydroxide followed by drying to obtain naphthalene sulphonate formaldehyde condensate. 2. A process as claimed in claim 1 wherein naphthalene is sulphonated with 98% sulphuric acid to produce naphthalene sulphonic acid which is then condensed with formaldehyde at a temperature in the range of 60-110°C for a time period in the range of 10-20 hrs. 3. A process as claimed in claims 1-2 wherein formaldehyde condensate of naphthalene sulphonic acid is neutralized with alkali metal hydroxide to a pH of 7.0-9.0. 4. An improved process for the production of naphthalene sulphonate formaldehyde condensate additive for coal water slurry fuels substantially as herein described with reference to the example.

Full Text

The present invention relates to an improved process for the production of naphthalene sulphonate formaldehyde condensate additive for coal-water slurry fuels. The main usage of the invention is in the preparation of high concentration coal-water slurry fuel achieving desirable flow property and stability.
Reference may be made to patent Nos.JP 1062392 dated 08.03. 1989 and JP 1054097
10.3. 1989 wherein additives for coal water slurry (CWS) containing compounds
prepared by sulphonating (alkyl) naphthalene, anthracene and biphenyl and condensing
with formaldehyde & fatty acids, have been described.
Reference may also be made to patent Nos. JP5271674dt. 19.10.1993, JP 1062391 dt

08.03.1989, JP 1054097 dt.01.03. 1989, JP 1182392 dt.20.07.1989 and JP 63156891
dt.29.06. 1988, wherein additives for coal water slurry - containing formaldehyde condensates of naphthalene/(alkyl) naphthalene sulphonic acids, fatty acids and polyethylene polyamine fatty acid amide compounds or compounds obtained from ethylene oxide and alkyl phenol/ polyhydric alcohols etc, have been described. The drawbacks of the above processes are that reactions have to be carried out in several stages with various types of specific compounds and the final additive package requires extensive pretreatment and selective purification methods, thus making the process tedious and uneconomical. Besides, the performance of the additive packages was not upto the desired level. Owing to these disadvantages of naphthalene based additives, the Japanese developed an efficient additive, namely sodium polystyrene sulphonate (PSS) which is used for commercial production of coal-water slurry (Ref. H.Arai and T.Ukigaki, Proc.16 Int. Tech. Conf. Coal Utilisation and Fuel System, Florida(1991) 423-433 ). PSS being the proprietary additive package of a Japanese
company, its preparation methods are fully guarded and the additive is highly expensive Reference may also be made to work of J.L. Morrison, B.G.Miller and A.W. Scaroni, Proc. 18 Int. Tech. Conf. Coal Utilization and Fuel Systems, April 26-29(1993) 361-368, Florida, U.S.A., wherein an ammonium based sulphonated naphthalene condensate has been used a s the dispersant for coal-water slurry fuels. However, the slurry formulation with this dispersant requires a pH modifier & a stabilizer.
The main object of the present invention is to provide an improved process for the production of naphthalene sulphonate formaldehyde condensate additive for coal-water slurry fuels which obviates the drawbacks as detailed above.
Another object of the present invention is to remove the tedious pretreatment and purification steps involved in hitherto known processes for the preparation of sulphonated naphthalene/alkyl naphthalene based additives.
Still another object of the present invention is to develop an additive package most suited to low-rank Indian coals for production of coal water-slurry fuels having desired viscosity and stability.
Yet another object of the present invention is to develop a low-cost, environmentally safe naphthalene based additive package.
Accordingly the present invention provides an improved process for the production of naphthalene sulphonate formaldehyde condensate additive for coal-water slurry fuels which comprises; characterized in that sulphonation of naphthalene at a temperature in the range of
130-165°C for a time period in the range of 2-8 hrs, condensing the resulting naphthalene sulphonic acid with formaldehyde, cooling to ambient temperature and neutralizing the condensation product with alkali metal hydroxide followed by drying to obtain naphthalene sulphonate formaldehyde condensate.
In an embodiment of the present invention naphthalene is first sulphonated with 98% sulphuric acid to produce naphthalene sulphonic acid which is then condenesed with formaldehyde at a temperature in the range of 60-110°C for a period in the range of 10-20 hours.
In another embodiment of the present invention the formaldehyde condensate of naphthalene sulphonic acid is neutralized with alkali metal hydroxide to a pH of 7.0-9.0
In this process, naphthalene is sulphonated with 98% sulphuric acid in the temperature range of 130-165°C for 2-8 hours. The naphthalene sulphonic acid produced is then condensed with formaldehyde at 60-110°C for 10-20 hours. The condensed mass is neutralized with alkali metal hydroxide to a pH 7.0-9.0 and then dried to obtain naphthalene sulphonate formaldehyde condensate which is used as an additive in the formulation of coal-water slurry fuel.
The novelty of the present invention with respect to the prior art lies in that the process provides a state of the art technology for the production of a naphthalene based additive which apart from being cost-effective is very efficient and environmentally safe agent and is also most suited to the lowO-grade Indian coals for the production of coal water slurry fuels. This additive is capable of incorporating high coal-loadings (60-70%) in the aqueous medium providing desirable viscosity and stability to the slurry fuel.
The inventive steps are--
1. The process which is apart from cost effective is very efficient and environmentally
safe agent.
2. The process is most suited for to the low grade Indian coals for the production of coal
water slurry fuels.
3. The additive used is capable of incorporating high coal- loadings(60-70%) in the
aqueous medium providing desirable viscosity and stability to the fuel.
The following example is given by way of illustration of the present invention and therefore should not be construed to limit the scope of the present invention.
EXAMPLE-1
533 gms. of 96% naphthalene is melted, 440 gms. of 98% sulphuric acid is added gradually to it and temperature of sulphonation reaction maintained at 160°C for 5 hours. The sulphonated mass is cooled and 220 ml water is added. To this mixture 228 ml formaldehyde solution (37%) is added slowly, the temperature is raised to 75°C and the reaction is carried out for 20 hours. At the end of this period the mixture is gradually heated to 110°C.The reaction product is cooled to ambient temperature and then neutralised with aqueous sodium hydroxide solution. The neutralised mass is dried to get sodium naphthalene sulphonate formaldehyde condensate which functions as an excellent additive in the formulation of coal water slurry fuels.
The invention has led to a simple process for the production of naphthalene sulphonate formaldehyde condensate which apart from being cost-effective, is an environmentally safe agent for use as an additive in the formulation of coal water slurry fuel. Secondly, the process steps have been reduced to a minimum and no by-products or any effluent are produced in the process. Thirdly, the reactions are carried out at relatively lower ranges of temperatures and at atmospheric pressure thereby leading to considerable savings in energy consumption in the process. The salient features of the invention which have an edge over the known processes are :
1. That the main feedstock naphthalene as well as other reactants are easily and
cheaply available.
2. The consumption of raw materials are considerably less.
3. The reactions are carried out at relatively lower ranges of temperatures and at
atmospheric pressure thereby reducing the energy consumption.
4. No effluent is produced in the process making it an eco-friendly.
5. The developed additive packag^ functions excellently at concentration of 0.6-
1.00%(on dry coal basis) with low- rank Indian coals incorporating high coal-loadings (60-70%) in aqueous slurry and providing desirable flow property/viscosity as well as stability to the slurry fuel.
6. The additive has a shelf life / stability of 9-22 days and viscosity in the range of
400-1000 mPas at 128 sec-1

We Claim:
1. An improved process for the production of naphthalene sulphonate formaldehyde
condensate additive for coal-water slurry fuels which comprises; characterized in that
sulphonation of naphthalene at a temperature in the range of 130-165°C for a time period
in the range of 2-8 hrs, condensing the resulting naphthalene sulphonic acid with
formaldehyde, cooling to ambient temperature and neutralizing the condensation product
with alkali metal hydroxide followed by drying to obtain naphthalene sulphonate
formaldehyde condensate.
2. A process as claimed in claim 1 wherein naphthalene is sulphonated with 98% sulphuric
acid to produce naphthalene sulphonic acid which is then condensed with formaldehyde
at a temperature in the range of 60-110°C for a time period in the range of 10-20 hrs.
3. A process as claimed in claims 1-2 wherein formaldehyde condensate of naphthalene
sulphonic acid is neutralized with alkali metal hydroxide to a pH of 7.0-9.0.
4. An improved process for the production of naphthalene sulphonate formaldehyde
condensate additive for coal water slurry fuels substantially as herein described with
reference to the example.

Documents:

168-del-2001-abstract.pdf

168-del-2001-claims.pdf

168-del-2001-correspondence-others.pdf

168-del-2001-correspondence-po.pdf

168-del-2001-description (complete).pdf

168-del-2001-form-1.pdf

168-del-2001-form-19.pdf

168-del-2001-form-2.pdf

168-del-2001-form-3.pdf

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Patent Number

217838

Indian Patent Application Number

168/DEL/2001

PG Journal Number

17/2008

Publication Date

25-Apr-2008

Grant Date

29-Mar-2008

Date of Filing

16-Feb-2001

Name of Patentee

COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH

Applicant Address

RAFI MARG, NEW DELHI-110001, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	KUMARESH CHANDRA BIT	C.F.R.I, P.O. F.R.I., (DHANBAD), PIN-828108, BIHAR.
2	SOMNATH BANERJI	C.F.R.I, P.O. F.R.I., (DHANBAD), PIN-828108, BIHAR.
3	KAMLESH KUMAR MISHRA	C.F.R.I, P.O. F.R.I., (DHANBAD), PIN-828108, BIHAR.
4	KAUSHAL KISHORE TIWARI	C.F.R.I, P.O. F.R.I., (DHANBAD), PIN-828108, BIHAR.

PCT International Classification Number

C10L 1/32

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA